Abstract

Surprise and change are the way of the world. Philosophers have known this at least since Thales, and practical men knew it long before. Variety and the continual flux of one thing into another is, for Peirce, a central notion. A very similar conception underlies the information-gap theory of uncertainty and its application to decisions with severely deficient understanding which I have argued for earlier. For Haack, whose treatment of warrant is strongly non-probabilistic, info-gap theory is a natural context. The connection between Peirce, Haack and info-gap theory is explored in this paper.